Electrical sockets may be used to secure electronic packages and/or integrated circuit (IC) devices, for example, onto a system board (e.g., a motherboard or a printed circuit board "PCB") of a computer system. These electrical sockets may be constructed for easy installation and replacement of electronic packages (e.g., electrical components) and/or integrated circuit (IC) devices, such as complex memory chips and advanced microprocessor chips. The electrical sockets may also be available in different sizes and configurations, including, for example, low-insertion force (LIF) sockets and zero-insertion force (ZIF) sockets.
Low-insertion force (LIF) sockets may be suitable for detachably securing traditional electronic packages and/or integrated circuit (IC) devices with low pin counts onto a system board of a computer system. However, zero-insertion force (ZIF) sockets are more desirable for advanced electronic packages and/or IC devices which have larger pin counts, since no or zero insertion force and removal force are required. For example, advanced microprocessor chips with high pin counts are typically installed in a zero-insertion force (ZIF) socket which is soldered directly to a system board of a computer system. The ZIF sockets are commonly used to secure advanced microprocessor chips onto a printed circuit board (PCB). This is because the advanced microprocessor chips may be accommodated without fear of damaging the chips or the electrical pins (connections) of the microprocessor chips which provide electrical contacts from the microprocessor chips to the system board.
A ZIF socket may typically include a release handle which, when open, permits easy installation of an electronic package and/or an IC device such as a microprocessor chip into the socket. Subsequent closure of the handle may secure the microprocessor chip in place. A heat sink may be then affixed on top of the microprocessor chip installed in the ZIF socket by mechanical means, such as a retainer clip, for dissipating the heat generated from the microprocessor chip. The heat sink may contain a thermally conductive heat sink in a form of a flat plate, generally of the same size as the microprocessor chip, and a plurality of cooling (radiation) fins extending upwardly from the flat plate. A heat sink fan may then be utilized to increase thermal dissipation of the heat sink member and maintain the temperature of the electronic package and/or the IC device at an acceptable level.
However, these commonly available ZIF sockets used for securing an electronic package and/or an IC device onto a system board of a computer system contain several disadvantages, especially in cases where an open or unprotected semiconductor die is used. First, the electronic package or IC device such as the microprocessor chip must be properly installed on the ZIF socket, and then the heat sink must be aligned properly with the ZIF socket, and then packaged carefully and squarely on top of an open die microprocessor chip in order to prevent damage to the open die microprocessor chip during assembly due to uneven loading and to ensure correct microprocessor operation. In practice, however, the heat sink may often (e.g., during hasty manufacturing/assembly practice) be slammed down onto an open die microprocessor chip at an angle with often excessive forces during assembly. As a result, an open die microprocessor chip can occasionally be damaged (e.g., ranging from edge chipping to major die cracks). Thermal interface material applied on the surface of the microprocessor chip for increased thermal coupling efficiency with a heat sink can frequently be scratched or disrupted. Secondly, separate steps are needed to secure an electronic package on the ZIF socket and a heat sink on the electronic package which may be burdensome. Lastly, selected portions of cooling fins of the heat sink may be eliminated to provide clearance for separately provided clips so as to secure the heat sink onto an open die microprocessor chip. The additional clips used to secure the heat sink onto an open die microprocessor chip can be unreliable and costly. Likewise, the elimination of cooling fins directly above the microprocessor chip can lessen the thermal performance and efficiency of the heat sink. Accordingly, there is a need to provide an advanced ZIF socket having heat sink retention and alignment features that can prevent the heat sink from damaging an open die microprocessor chip due to uneven loading and/or excessive forces during assembly, and eliminate the separate assembly of an open die microprocessor chip, a heat sink and an additional clip used to secure the heat sink in place while maximizing the thermal performance of the heat sink.